Digital frequency synthesizers are known in the art and typically include at least one look-up table which stores digital samples of the sine or cosine function waveform to be generated. In the past, large look-up tables have been used to store a large number of digital samples of the sine or cosine function waveform along a complete cycle of the waveform. The digital frequency synthesizers are responsive to input and output sequentially the digital samples stored in the look-up table thereby to output a complete cycle of the sine or cosine function waveform. The digital output of the synthesizer may of course be conveyed to an analog to digital converter to convert the digital output to analog form.
Although digital frequency synthesizers of this nature have allowed for the generation of high resolution sine or cosine function waveforms, the use of large look-up tables to store a large number of digital samples has maintained the power consumption levels of these digital frequency synthesizers relatively high. Accordingly, digital frequency synthesizers which reduce power consumption yet generate high resolution sine or cosine function waveforms are desired.
It is therefore an object of the present invention to provide a novel low power direct digital frequency synthesizer.